webProeasy

Meme Contest

alfactf

Task: Meme voting platform requiring 1337 votes to win. Solution: Captcha bypass via None-to-string type confusion - str(session.get("captcha_text")) returns "None" when not set, allowing votes with captcha_input="NONE" without visiting the captcha page.

flask captcha_bypass session_manipulation type_confusion python none_string voting_manipulation logic_flaw

Captcha bypass via None-to-string type confusionSession state manipulationAutomated voting with parallel requests

$ ls tags/ techniques/

flask captcha_bypass session_manipulation type_confusion python none_string voting_manipulation logic_flaw

Captcha bypass via None-to-string type confusionSession state manipulationAutomated voting with parallel requests

Analysis

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$ python3 exploit.py --target 192.168.1.1 --port 8080
[*] Connecting to target...
[+] Shell obtained!

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